A conventional welding device comprises a welder power supply for powering a welder that performs arc-welding or the like, and a setter for setting a welding condition of the welder power supply through remote operation. The setter is assigned individually to a specific welder power supply, and allows setting and displaying only predetermined welding conditions as well as powering conditions performable by the welder power supply.
The conventional welding device disclosed in Patent Literature 1 is described hereinafter with reference to FIG. 11, which depicts schematically a structure of the conventional welding device. FIG. 11 shows setter 101 and welder power supply 102 of the welding device, and omits other sections of a welder such as a weld-output section necessary for arc welding.
In FIG. 11 setter 101 is formed of current adjuster 103 for adjusting a welding current, voltage adjuster 104 for adjusting a welding voltage, and welding-method switcher 105 which switches a welding method from one to another. Two switchers 105 shown in FIG. 11 work together as a unit. Welder power supply 102 includes current control circuit 107 to which a signal from current adjuster 103 is supplied, voltage control circuit 108 to which a signal from voltage adjuster 104 is supplied, and switching circuit 109 to which a signal from switcher 105 is supplied. The welding method includes, e.g. Co2 automatic arc welding method, arc gouging method, and manual welding method. These methods can be switched from one to another with switcher 105. Setter 101 is coupled to welder power supply 102 with cable 106, and carries out setting or changing a welding method, welding current, and welding voltage.
The length of cable 106 between setter 101 and welder power supply 102 is several meters or sometimes 10-odd meters, so that a user can change a content set in welder power supply 102 through remote operation.
Before starting a welding, it is necessary to set welding conditions to welder power supply 102 according to the characteristics of a target object which is to be welded. The welding conditions chiefly include, e.g. a welding method, welding current, welding voltage. Use of conventional welder power supply 102 and setter 101 needs to switch welding-method switcher 105 for switching the welding method from one to another. In this case, when switcher 105 selects contact 105a, welding-method switching circuit 109 determines to use the Co2 automatic arc welding method. In a similar way, selection of contact 105b prompts switching circuit 109 to determine to adopt the arc gouging method, and selection of contact 105c prompts switching circuit 109 to adopt the manual welding method. The conventional welding device thus switches the welding method from one to another among the foregoing three methods with a switching signal transmitted from setter 101.
However, if a welding method other than the foregoing three methods is added to welder power supply 102 through altering a software program for welding, conventional setter 101 cannot select this additional method because welding-method switcher 105 has no contact corresponding to this additional method.
The welding conditions include, other than the welding method, a welding wire diameter, a base material of the target object, a control method. When the conventional welding device changes these conditions or adds a new condition, other than the welding method, through altering the software program for welding, the foregoing reason prohibits the welding device from selecting these conditions changed or added because setter 101 is assigned to specific welder power supply 102 individually.
To overcome this problem, it is possible to increase the number of contacts in switcher 105 of setter 101; however, this measures needs to modify setter 101, and setter 101 having a greater number of contacts must expressly replace conventional setter 101 which has been used before a welding condition is added.
On top of that, the problem discussed above can also happen when a welding output capacity of power supply 102 is changed. In this case, instead of modifying or replacing setter 101, it is possible to use a variable resistor (not shown) provided to conventional setter 101 for adjusting the current or the voltage in order to comply with the change in the welding output. However, although the variable resistor is kept at the same voltage as before the capacity of power supply 102 is changed, an actual current or voltage supplied from the changed power supply 102 differs from what is expected.
As discussed above, when another welding method is added to welder power supply 102 or an output capacity of power supply 102 is changed, the conventional welding device cannot use setter 101 anymore, which has been used before these changes with power supply 102. In other words, since setter 101 is assigned to specific welder power supply 102 individually, if another welding condition is added to power supply 102 or a capacity of power supply 102 is changed, setter 101 must be replaced or modified in order to comply with the new conditions.    Patent Literature 1: Unexamined Japanese Patent Application Publication No. H10-109166